Nozzle



Oct: 21, 1930.

L. NEGRO NOZZLE Filed Jan. :51, 1929 Patented Oct. 21, 1930 PATENT OFFICE LUIGO NEGRO, F BUCHAREST, RUMANIA NOZZLE Application filed January 31, 1929, Serial No. 336,610, and in Italy February 15, 1928.

"calculation may be kept up in any form or structure (such as devices for pushing and hoisting, turbines, etc), and the control of the'liquid, gas or steam is effected on a large scale without changing the measure or degree of conicity.

My present improved nozzle comprises two cones, the one engaged in the other, one of which is adapted to slide, and adjustable by means of a rod so that not only the relation between the outlet F 2 and inlet F is constant, but practically also the measure of conicity equal to where Z is the distance between the two open ings F and F I have illustrated my invention byway of example in two of its modifications in the annexed drawings where Fig. l is a symmetrical section of an ordinary nozzle for aeriform fluids,

Fig. 2 is also a symmetrical section, but of an improved nozzle according to my present invention, and Fig. 3 shows a second modification thereof.

With reference to Fig. 1 and particularly its reference letters it is to be observed that when using nozzles to the smallest passage section F of which gradually broadens, there are two rather serious drawbacks, namely:

1. It is known that to a certain given rela tion between the pressure P of the driving fluid (steam, compressed air, gas, etc.) ahead of the outlet, and the pressure P of chamber C placed past the nozzle corresponds a certain degree of conicity determined by the surfaces F and F and by the length Z, and since the angle a of the diverging part ought to be as much as possible in accord with the material inclination of the steam, it is just possible that in certain cases, such as e. g. the case of the example illustrated in Fig. 1, the length Z of the diverging part of the nozzle,as in correspondence with a determined value of L, part Z should not be of unallowable dimensions,becomes so large that the device owing to its highly unsatisfactory efficiency is practically useless.

2. Generally the quantity of liquid, steam or gas is controlled by the needle 6. From the above it Will be seen that after having established the values F -F and Z when the area of section F of the outlet is reduced by the introduction of the control needle, the predetermined relation between the three values F 2 F and Z is varied and the efliciency is reduced to practically unallowable values.

My present invention relates to a nozzle type in which the relations resulting from calculation may actually be utilized and the 06 controlling of the liquid may be effected on a large scale without exceeding the limits resulting from calculation for the degree of conicity.

The device according to my present invention, Fig. 2, comprises a cylindrical body 1, within which a cone 2 is fixed to a point 7 in any suitable mechanical way. In the cylinder 1 slides a ring 3 controllable by a rod 4. The outer surface of ring 3 is cylindrical, whilst the inner surface is conical so that the ring forms an annular space with cone 2, and in correspondence with a determined value of Z the smallest section ares F m passes to the value F which has been fixed by calculation of the nozzle. The said annular space is more or less large according to the ring 3 being shifted upwards or downwards by the needle 4 rotating in the boss 6 connected to ring 3 by wings 7 It is obvious that the above described arrangement permits of making nozzles the length Z of which most corresponds to a high efliciency of the device. The further advantage is obtained that the degree of conicity is practically constant for any admission of driving fluid, which is not obtainable by ordinary nozzles controlled by a needle as shown in Fig. 1.

It is understood that the modification shown in Fig. 2 may be varied without varying the purpose aimed at,.as is shown e. g. in Fig. 3 where ring 3 is fixed to ring 1, and its cone is movable and operated by rod4.

Having now particularly described and ascertained the nature of my said invention and z in what manner the same is to be performed I declare that what I claim is:

A nozzle including an outer hollow cone and an inner cone, said nozzle Widening in section in the direction of the fiow therethrough between the cones, the inner cone being engaged in the hollow cone and both being reciprocallyslidable for adjustment, the nozzle being so shaped and the reciprocal 7 position of the cones so arranged that when reciprocally sliding on the one hand the ratio between the outlet and the inlet section is substantially invariable, and on the other hand the measure of conicity is practically constant.

LUIGI NEGRO. 

